The present invention relates generally to inkjet printers, and more particularly to an inkjet printer including a carriage drive belt having a compliant belt section which provides for carriage attachment.
A conventional inkjet printing system includes a printhead assembly, an ink supply which supplies liquid ink to the printhead assembly, and an electronic controller which controls the printhead assembly. The printhead assembly, commonly referred to as a print carriage or a pen, ejects ink drops through a plurality of orifices or nozzles and toward a print medium, such as a piece of paper, to print onto the print medium. Typically, the orifices are arranged in one or more arrays such that properly sequenced ejection of ink from the orifices causes characters or other images to be printed upon the print medium as the printhead assembly and the print medium are moved relative to each other.
To position the printhead assembly relative to the print medium, the conventional inkjet print system includes a carriage assembly. Typically, the carriage assembly includes a carriage and a carriage drive assembly. As such, the printhead assembly is positioned in, and supported by, the carriage and the carriage drive assembly moves the carriage and, therefore, the printhead assembly back and for the across the print medium.
As illustrated in FIG. 1, a conventional carriage drive assembly 200 typically includes a drive pulley 202, a drive belt 204, an idler pulley 206, and a belt tension spring 208. The idler pulley is spaced from the drive pulley, and the drive belt extends between and around the drive pulley and the idler pulley. The drive pulley is attached to a drive motor (not shown) by a drive shaft 210 to transfer power to the drive pulley and the drive belt. Power transfer from the drive pulley to the drive belt moves a section of the drive belt back and forth between the drive pulley and the idler pulley. Typically, the drive pulley and/or the idler pulley has a reciprocal toothed contour designed to mate with the toothed contour of the drive belt. A carriage 212 (only a portion of which is illustrated in FIG. 1) is attached to the drive belt such that the carriage moves with the drive belt between the drive pulley and the idler pulley.
One arrangement for providing a pre-load tension in a drive belt was included in the ScanJet 6300C/Cse/Cxi series scanners produced by Hewlett-Packard Company of Palo Alto, Calif., the present assignee. This arrangement included a coil spring wound in a direction perpendicular to a length of the drive belt with projecting arms at opposite ends which were hooked over the drive belt. This arrangement, however, is unsuitable for drive systems requiring high acceleration, such as an inkjet printing system, because the arms will deflect before the coil spring windings thereby reducing a desired pre-load tension in the drive belt and resulting in slip between the drive belt and the drive motor pulley.
As the carriage is attached to the drive belt, vibrations or pulsations from the drive motor which are generated, for example, while the carriage is accelerated from rest can create a resonant condition. As such, these vibrations or pulsations can be transferred to the carriage and, therefore, the printhead assembly, which in turn can affect image quality.
For these and other reasons, there is a need for the present invention.
One aspect of the present invention provides a carriage drive belt for moving a carriage. The carriage drive belt includes an elongated belt section having a longitudinal axis and including a first portion and a second portion spaced from the first portion along the longitudinal axis, and a compliant belt section secured to the elongated belt section, wherein the compliant belt section extends between the first portion and the second portion of the elongated belt section and is configured for attachment of the carriage thereto.